build: Enable ProGuard (#1650)

android/app/proguard-rules.pro

@@ -0,0 +1,23 @@
+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.kts.kts.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# These packages are referenced by ReVanced Patches
+-keep class app.revanced.patcher.** { *; }
+-keep class com.android.tools.smali.** { *; }
+-keep class kotlin.** { *; }
+-keepnames class com.google.common.collect.**
+
+# This package uses reflection internally, so do not remove and rename
+-keep class com.android.apksig.internal.** { *; }
+
+# Fix crash
+-keepnames class org.xmlpull.** { *; }
+
+# Fix build errors
+-dontwarn java.awt.**
+-dontwarn javax.**
+-dontwarn com.google.j2objc.annotations.*